Fig. 9
From: Primary cilia promote the differentiation of human neurons through the WNT signaling pathway
The ciliary WNT signaling pathway regulates the expression of cyto-architectural remodeling genes during neuron differentiation. qRT-PCR analysis of the expression of WNT signaling pathway output genes following pathway inhibition (antagonist Wnt-C59) or activation (agonist Wnt-3a) reveals clear gene expression differences in LUHMES WT neurons as compared to RFX2 -/- neurons with an altered primary cilium. A WT neurons treated with Wnt-C59 show strong downregulation of genes implicated in cyto-architectural organization, including the non-canonical WNT signaling pathway output genes CAMK2A and DAAM1: expression levels are very similar to the basal expression levels of untreated RFX2 -/- neurons (vehicle). B Treatment with a WNT activator (Wnt-3a) results in stronger upregulation of canonical output genes in WT neurons as compared to in the RFX2 -/- background. C qRT-PCR analysis of the expression of a set of canonical WNT signaling pathway output genes (Note: PTK7 is also as non-canonical target gene) following pathway inhibition (antagonist Wnt-C59): for this set of output genes WT neurons treated with Wnt-C59 do not show downregulation of gene expression and their expression levels are very similar to the basal expression levels of untreated (vehicle) RFX2 -/- neurons with an altered primary cilium (exceptions: neuron differentiation markers NEUROG1 and PAX6). These results point toward an involvement of the non-canonical WNT signaling pathway in neuron differentiation to promote cytoskeletal rearrangement and remodeling. Mean values are shown ± s.e.m. (normalized to GAPDH; not shown). The results are from a minimum of three independent experiments with two technical replicates each. We conducted regular two-way ANOVA analyses (not repeated measures) with multiple comparisons (Bonferroni’s test) between groups. *p < 0.05; **p < 0.005; ***p < 0.0005; ****p < 0.0001